Dices over network.

Hi everyone,
I've got an big issues, and I spend days to find an answer but nothing works..
So at the beginning of my game, I've got an small mini-game where everyone roll a dice to decide which player is the first.

And I found no way to synchronise the number with every client! I tried, RPC, Sync Hook, everything I found on the internet..
Here is my current not working script..

Code (CSharp):

usingSystem.Collections;

usingSystem.Collections.Generic;

usingUnityEngine;

usingUnityEngine.UI;

usingUnityEngine.Networking;

publicclass RandomDice : NetworkBehaviour {

public Text Number;

//[SyncVar(hook = "TextOnServer")]

publicstring RndmNumber;

publicvoid RandomNumber(){

TextOnServer(Random.Range(1, 7).ToString());

}

privatevoid Update()

{

Number.text= RndmNumber;

}

void TextOnServer(string DiceNumber){

Debug.Log(DiceNumber);

RndmNumber = DiceNumber;

Number.text= RndmNumber;

}

}

It would be very kind of you to explain to me, show me exemples, to make it work.. thank you very much.